GitHub splits VS Code Agents usage from Copilot's Agent Mode

GitHub split its Copilot usage metrics API on September 11, adding four fields that track VS Code's dedicated agent window apart from the editor's Agent Mode, per GitHub's changelog post.

Any dashboard summing usage fields now undercounts unless it also pulls the VS Code Agents counters, since the API doesn't merge them. Teams tracking Copilot adoption through the API need to add the new fields explicitly, since older queries won't return VS Code Agents activity.

The new fields are daily_active_vscode_agent_users, an org-level totals_by_vscode_agent, a per-user used_vscode_agent flag, and a per-user totals_by_vscode_agent covering session counts and user messages.

All four fields are optional in the API response. The changelog says VS Code Agents usage stays out of editor-window Agent Mode and out of Copilot's general usage rollups.

The changelog doesn't say what prompted the split or whether the two counters will eventually converge.